Projection apparatus



H. F. KURTZ PROJECTION APPARATUS Sept. 10, 1940;

Filed Sept. 21, 1938 4 Sheets-Sheet 1- I 6 TM. m 5 4 w HENRY F.KURTZ m ENTO% BY 1L Sept. 10, 1940. H. F. KURTZ 2,214,376

' .PROJEGTI N APPARATUS Filed Sept; 21, 1956 4 ShQets-Sheot HENRY F. KURTZ INVENTO |NVENTQR II llHll I I H Um.

Filed Sept. 21, 1938 I I I I l I I I l Patented Sept. 10, 1940 UNITED, STATES PROJECTION APPARATUS Henry F. Kurtz, Rochester, N. Y., assignor to Bausch & Lomb Optical Company, Rochester, N. Y., a corporation of New York Application September 21, 1938, Serial No. 231,023

6 Claims.

. The present invention relates to optical instrument's and more particularly to contour meas uring projectors.

One of the objects of the present invention is to provide a rugged and precise contour measuring projection apparatusin which the optical elements are convenient and accessible for changing or cleaning. Another object is to provide a new and improved lens mount for a contour measuring projector. A further object is to -provide a new and improved illuminating system for a contour measuring projector.- These and other objects and advantages reside in certain novel features of construction, arrangement and combination of parts as will hereinafter be more fully set forth and pointed out in the appended claims.

Referring to the drawings: I Fig. 1 is a perspective'view of a contour measuring projector embodying my invention.

Fig. 2 is a fragmentary vertical section of the lower part thereof.

Fig. 3 is a section taken on line 33 of Fig. 2.

Fig. 4 is a section taken on line 44 of Fig. 2.

Fig. 5 is a wiring diagram of the stage moving mechanism. i

Fig. 6 is a fragmentary vertical section of the upperpart of my projector.

Fig. 7 is an enlarged vertical section of the lens wall and a hollow sub-base I3 having an upright portion I4 is secured inthe opening I2 by bolts l5 which extend through the base In. The

45 upright portion I4 is provided with a vertical opening I6 and two vertical bearing-guides I1 and H' has an opening l2 in the lower part of its front other supports can be readily substituted. The stage 23 illustrated is flat and horizontal and is provided with an aperture 25 within which is secured a glass plate 26. I

Within the casing 20 isja tubular compartment 5 21 which has an opening 28 through which a water cell 29 may be inserted. A cap 30 serves to close the opening 28. Of course a plurality of water cells), filters or the like can be placed in the compartment 21 if desired. v i 10 The plate 2| is recessed around the end of the compartment 21 and a threaded ring 3| is fixed in the recess by screws or bolts 32. A tube 33 threaded into the ring. 3| extends rearwardly through the opening it and carries at its outer 15 end a lamp housing 34 within which is mounted a suitable. lamp 35 such as a tungsten arc lamp.

A suitable condensing system 36 is slidably mounted in the tube 33 and this system is adjusted by means of the handle-3l preferably until 20 the light rays from the lamp 35 are substantially parallel. Of course the rays could be converging or diverging but I prefer a substantially parallel 'beam.

A suitable reflector 38 is fixed on a stub shaft 25 39 by a set screw 40 and this stub shaft is fixed in an opening 4| in the wall of the casing 20 by a set screw 42. The reflector 38 is so positioned that it receives the light rays through the compartment 21 and directs them vertically upward 30 through the aperture 25 in the stage or object support 23.

A nut 43 is securedin an opening 44 at the bottom. of the casing 20 by bolts 45 and a vertical screw 46 is threaded in this nut. This screw is rotatably journallcd ina bearing 41 which is secured on the sub-base by bolts 48. The screw- 48' is rotated by a gear 49 fixe'd at its lower end within the sub-base i3 and which in turn is driven by a gear 50 rotatably mounted on a stud 5|. 40 A gear 52 fixed on a shaft 53 serves to drive the gear 50.

The shaft 53 carrying the gear 52, is rotatably journalled at its lower end in a bearing 54 car- 'ried by a bracket 55 secured to the sub-base I3. 45

This shaft 53 extends upwardly through a hole 56 in the sub-base l3 and is directly connected .to a shaft 57. A motor 58 drives the shaft 51 through suitable reduction gearing indicated generally at 59. t I The motor circuit shown in Fig. 5 is substantially the same as themotor circuit described and claimed in U. S'Patent No. 2,065,952 issued December 29, 19365 to Otto E. Trau tmann. This circuit consists of two wires 60 and BI which are 55 connected to a source of power and which lead,

, respectively, to a switch contact 62 and one side of the armature 63 of the motor 58. The field of the motor 58 is split into two opposed windings B4 and 65 so that when the contact 66 is closed against the contact 62, the field winding 64 will be energized and the motor I5 will rotate in one direction while closing the contact 6'! against the contact 62 energizes the field winding 65 and causes the motor I5 to rotate in the opposite direction. The contacts 66 and 81 are actuated by push buttons 68 and 69, respectively, carried by a switch box I0 mounted in'a convenient position on the front of the apparatus just above the bearing guide I8.

In order to limit the movement of the casing 20 to predetermined limits, a switch II which is normally closed, is placed in the circuit with the field winding 64 which causes the motor 58 to rotate in the direction to lower the casing 20. A suitable projection 72 is secured on the table 33 and, when the casing 20 reaches the predetermined lower limit of its travel, this projection opens the switch H and thus stops the motor 58. A similar projection I3 and a similar, normally closed switch I4 in the circuit with the field winding 65, serve to limit the upward movement of the casing 28 under the actuation of the motor 58.

The optical system for forming an image of an object supported by the stage 23 is illustrated in Figs. 1, 6, 7 and 8. Above and beyond the path of travel of the casing 28 and stage'23, the front wall of the housing II is provided with an opening I5. A tube I6 is pivotally mounted on a hinge pin TI which is secured to the front wall of the housing .II above the opening I5. Normally, the tube I6 swings downwardly on the.

hinge pin 11 forming a light tight connection with the housing II about the opening 15.

The tube I6 extends outwardly from the housing II above the stage 23 and has a large opening 18 in its top at its outer end. The bottom wall of the tube I6 has an opening I9 in substantial alignment with the aperture 25 in the stage 23. A recess 80, surrounding the opening I9, forms a seat for receiving the flange 8| of a mount 82 carrying an objective lens 83.

A cover 84 for the opening I8 is hingedly connected at 85 at the outer end of the tube 16. A pin 86 which is slidably mounted in the cover 84 is urged by a spring 81 toward the lens mount 82. lens mount 82 is provided with a tapered notch 88 and the pin 86 engaging this notch 88 presses the flange BI firmly into the seating recess 80. A head 89 is fixed to the pin 86 to permit withdrawal of the pin 86 from the notch 88.

Directly above and in alignment with the opening 19, the cover 84 has a seat 90 for receiving a prismzSI. This prism 9| is preferably a right angle, roof prism as illustrated in U. S. Patent No. 1,934,582 mentioned above. The prism 9| is secured in its seat 98 by a strap 92 attached to the cover 84 by suitable screws or bolts 93.

Within the upper part of the housing II is a bracket 94 carrying two first surface reflectors 95 and 96 at right angles to each other. The reflector 95 receives the image beam-from the prism 9| and reflects it upwardly to the reflector 96 from which it is reflected to a translucent screen 97 in the front Wall of the housing II.

The screen 91 is mounted in a frame 98 and is carried by a ledge 99 on the front wall of the housing II. Thus it is apparent that the screen The upper surface of the flange 8I'of the 91 may be readily removed and other image receiving surfaces substituted. For example, a photosensitive sheet could be substituted and a photograph made of the object on the stage 23. Or the image of the object could be formed on a suitable drawing of the object to check the shape and dimensions.

The side wall of the housing I I is provided with two openings closed by doors I00 and IOI. The forward door I00 permits access to the light source 35 and motor 58 and a grid or screen I02 above the door I00 permits the escape of heat from the lamp 35 and motor 58.

The door IOI permits access to a suitable storage compartment in the housing II where various accessories such as lenses, stages or screens may be conveniently kept.

The lens 83, prism 9|, reflectors 95 and 96 and screen 9'! are all fixed relative to each other so that an object in the object plane -of the lens 83 will be imaged on the screen at a fixed magnification. The instrument is furnished with a series of lenses giving standard magnifications, for example, IOX, 25X, 50X and IO0X and the operator selects the lens giving the magnification desired. The cover 84 is opened by means of the handle 84' and the selected lens is dropped through the opening I8 so that its flange 8I seats in the recess 88. The cover 84 is then closed and the pin 86 engaging in the notch 88 forces the lens tightly into the seating recess.

The object to be projected is then placed on the stage 23 over the glass plate 26 and the lamp 35 is lit. The object is then brought into focus by pressing either the button 68 or the button 69 and operating the motor 58 to raise or lower "the stage 23 by means of the screw 50. During focusing, the operator should keep his eyes on the screen and stop the motor when the image is sharp. The hinged connection between the tube 16 and the housing II prevents any injury to the lens 83 or prism 9| in theevent that the object strikes the lens. A foot rest I03 on the front of the base I0 prevents scarring the base I0 or wearing ofi' the paint.

From the foregoing, it will be apparent that I am able to attain the objects of my invention and provide a new and improved contour measuring projector which is rugged and accurate in operation. Various modifications of structure can, of course, be made without departing from the spirit of my invention or the scope of the appended claims.

I claim:

1. A contour measuring projector comprising a base, a vertical objective lens carried by said base, an image screen, means for directing an image formed by said lens to said screen, an object support vertically movably mounted on said base beneath and in alignment with said lens, means for moving said object support vertically toward and from said lens to bring an object supported thereby into the focal plane of said lens, and a source of light'carried by and movable with said object support for illuminating an object being beneath and in a plane out of alignment with said lens, an object support vertically slidable in said guides and projecting outwardly therefrom into alignment with said lens, a tube and means arried by said object support, said tube proecting beyond said guides in the opposite direction from said object support, a light source carried by said tube, means for directing light from the source through the tube to the object support for moving the 'object support in said guides to bring an object carried thereby into the focal plane of said lens.

3. A contour measurmg projector comprising a base, a vertical wall carried by said base, a horizontally disposed stage vertically movably mounted on said wall, a source of light carried by said stage, means carried by having an opening in its a lens, lens positioning means within the holder, a

the stage for directing light rays from the source vertically upward through the stage, means for moving said stage vertically, a horizontal, hollow, tubular holder carried by said wall above the stage, said holder top wall for receiving lens carried by the positioning means for receiving light from said stage, a closure for said opening, reflecting means carried by said closure in alignment with said lens for laterally reflecting light rays from said lens, an image screen-vertically carried by said wall above said holder, and means for directing light from the reflecting means to said screen.

4. A projection apparatus for gaging and measu'ring objects comprising a support, means carried by said support for producing a vertical beam of light rays, a horizontally disposed stage adjustably mounted on said support for holding objects to be gaged in said beam, a holdermounted on said support abovesaid stage, said holder having an opening .for receiving a lens, lens positioning means within said holder, a lens carried by said positioning means, a closure mounted on said holder to close said opening, re-

flecting means carried by said closure in align uring objects tally disposed removably Q directing the light from the reflecting means to said screen.

5. A projection apparatus for gaging and meascomprising a support, a. horizonstage adjustably mounted on said support, means carried by said stage for producing a vertical beam of light rays, a horizontal tubular lens holder carried by said support above said stage, said holder having an opening in its top wall and a lens receiving aperture in its lower wall above said stage, a seat surrounding said aperture, an objective lens, a mount for said' lens, a flange extending outwardly from said mount to engage said seat, means for locking said lens in said seat, a closure for the opening, deflecting means carried by said closure for receiving light from said. lens and directing it through said holder, an image screen vertically carried by said support above said holder and means for directing the light from'said deflecting means onto said screen.

6. A jcontour measuring projector comprising a base, --a vertical objectivelens carried by said I base, an image screen, means for directing an im- 

